通过text.isEmpty确定空文本字段(Determine Empty Text Field via text.isEmpty)

通过text.isEmpty确定空文本字段(Determine Empty Text Field via text.isEmpty)

我试图触发模态segue如果文本字段为空，我有以下代码：

@IBAction func createUserButtonPressed(sender: UIButton) { if self.emailAddressTextField.text.isEmpty{ func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?){ if (segue.identifier == "ShowErrorSegue"){ } } } }

emailAddressTextField是文本字段，我想要学习的是，如果用户尝试在没有电子邮件地址的应用中创建帐户，则应该弹出一个弹出窗口。

即使文本字段为空，问题是（self.emailAddressTextField.text.isEmpty）也不返回true。 我在这里想念的是什么？

请建议。 谢谢。

I am trying to trigger a modal segue if the text field is empty for which I have following code:

@IBAction func createUserButtonPressed(sender: UIButton) { if self.emailAddressTextField.text.isEmpty{ func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?){ if (segue.identifier == "ShowErrorSegue"){ } } } }

emailAddressTextField is the text field and what I am trying to learn to do is that user should get a popup if they try to create an account in my app without email address.

The problem is (self.emailAddressTextField.text.isEmpty) doesn't return true even though the text field is empty. What am I missing here?

Please suggest. Thanks.

最满意答案

您可以只计算文本字段元素，也可以使用stringByTrimmingCharactersInSet方法删除任何空格：

if countElements(emailAddressTextField.text.stringByTrimmingCharactersInSet(.whitespaceCharacterSet())) > 0 { println("not empty") } else { println("empty") }

You can just count your text field elements and you can also get rid of any spaces using stringByTrimmingCharactersInSet method:

if countElements(emailAddressTextField.text.stringByTrimmingCharactersInSet(.whitespaceCharacterSet())) > 0 { println("not empty") } else { println("empty") }